Miniature electric motor for toy locomotives



A. E. KIRALFY 2,791,704

'MINIATURE ELECTRIC MOTOR FOR TOY LOOOMOTIvRs May 7, 1957 3 Sheets-Sheet 1 Filed June 27, 1955 l so 27 lo 4l ALEXANDER E. KIRALFX INVENTOR.

@CRM G, T/ 21 HIS ATTORNEY May 7, 1957 A. E. KIRALFY 2,791,704

MINIATURE ELECTRIC MOTOR FOB TOY LOCOMOTIVEJS Filed June 27, 1955 3 Sheets-Sheet 2 FIO-10- l /6 ,20 MMM) H la .ijf /7 ,24g 30 90b Il 321-340.

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29a 2gb :2 34- 3 ALEXANDER E. K/RALFY ;o ,g4 INVENTOR.

HIS ATTORNEY MINIATURE ELECTRIC MOTOR FOR TOY LOcOMOTIvEs Filed .June 27, 1955 A. E. KIRALFY May 7, 1957 3 Sheets-Sheet 3 ALEXANDER E. KIRALFY IN V EN T 0R.

BYfwf HIS ATTORNEY MINIATURE ELECTRICMOTOR FOR TOY LOCOMDTIVES Alexander Enrico Kiralfy, Los Angeles, Calif.

Application June 27,1955, `Serial No. 518,313

14 Claims. (Cl. 310--1) This invention relates to a miniature electric motor which is particularly :adapted for use in a toy locomotive, but which may be-also adapted for other uses and purposes.

lt is an object of my invention to provide a new and -improved electrically `operated .toy locomotive which is I simple `and economical to essemble and maintain and in which no close tolerances are required. `My device is so formed lthat it actually comprises an electric motor built the shape of a toy locomotive.

It is a further object of my invention to provide such a device in which the parts are independently removably mounted for speed and ease of assembly and repair.

Another object of myinvention is to 'provide a toy locomotive which is always self-startingbecause of the nature of the motor construction.

A fur-ther object of my invention is to provide such a device in which a minimum amount of electrical arcing can occur at the contact points, due to `the fact that the circuits of ythe motor coils are short-circuited instead of being opened when full current is flowing.

t is another object of my invention to provide such a toy locomotive in which the full amount of yapplied electrical current is used at all times to drive the locomotive.

It is Ialso :among the objects of my invention to provide a toy locomotive which can operate from dry cells, in which the speedcan be easilyand effectively controlled, which can operate with or without a trackv and which has drive on all wheels.

A further object of my invention is to provide a toy locomotive which develops a maximum amount of power, sutiicient sol that no pivotable trucks are necessary on either the locomotive or the cars pulled thereby. The power of my vlocomotive issuchthat its .speed is not greatly aliected by the steepness of a gratie or the weight of the load being pulled.

It is also an object of my invention to provide a means of producing an electrical toy train which is extremely miniature in size and Whichhlas no `separate electric motor, so that `all available space is utilized to obtain the greatest amount of electrical drive mechanism, with resultant increase in power per size ratio and yet retaining `a robust construction.

My invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by my invention.

While I have shown in the `accompanying drawings a preferred embodiment of my invention, it should be understood that the same is susceptible of modification and change without departing from the spirit of my invention.

Referring to the drawings,

Fig. 1 is `a top plan View of my toy locomotive with the top cover removed;

Fig. 2 is a side sectional view of the same taken substantially along line Z-2of Fig. 1;

Fig. 3 is a bottom. plan View of the ysame showing the right cam lobes in one contact arm engaging position;

2,791,704 Patented May 7, 1957 icc Fig. 4 is a similar view with the ends omitted, showing the left cam lobes in one contact armengaging position;

Fig. 5 is an identicalview with the right cam lobes in the opposite. position from Fig. 3;

Fig. 6 is an identical view ywith the left cam lobes in the opposite position from Fig. 4;

Fig. 7 is a sectional View of my toy locomotive taken substantially along line 7-7 of Fig. l;

z Fig. Sis anexplodedtop perspective view showing how the coils and contact members may be inserted into and removed from the body member of my toy locomotive;

Figs. 9-16 are a series of sequential views in which the coils, shaft, and permanent magnets are illustrated in perspective while the contacts are indicated schematically to` illustrate the magnet and contact positions and current liow which occur during one complete cycle of operation of the motor.

A preferred embodiment which has been selected to il lustrate my invention comprises a body member 16, which is .formed inthe elongated substantially rectangular shape of a conventional diesel electrictlocomotive. The body member 10 may be formed of plastic, metal, wood or other suitable material and may be provided with a removable top'cover.

.Body member It? includes afront contact. compartment 11 and a rear contacty compartment 12, which are disposed adjacent the opposite ends of bodyV member 10. A coil compartment 13 is disposed therebetween. The iloor of coil compartment 13 is provided with two pairs of loppositely disposed elongated slots 14, which are disposed'adjacent the sides kof body member 1i).

The held `member of a motor consists of a pair of electrical coils 1S and 16, each having a core with parallel oppositeiyvdisposed poles 17 and 18 and 19 .and 2i) respectively. The coils 15 and 16 are mounted so that the lower free `ends of the poles 17-20 extend through slots 14 to-adjacent the bottom of-body member 1li, while the remaining portions of the coils are disposed within `coil compartment 13.

- The field members with coils 15A and 16 are removably mounted in the body member 10, since they may be slid out fronrthe top obody member 10 whennthe top .cover thereof vis removed. The coils 15 and 16 are so dimensioned thatthey fill the entire space of coil.com partment 13. vThe side edges of coils 15 `and 16 are in Vsubstantial contact with the ends lof-compartment 13 and in a vertical direction adjacent the Iside of body member 10. The grooves 21 extend from thek top of bodyV member 10 to the tloor of compartment 11. The loor of compartment 11 is provided with two substantially rectangular openings 22 and 23.

A Contact element 24 comprises a substantially square flat backplate' 25, a-narrowertop portion Zran'd a pair of elongated contactharms 27 and 28. Contact element 24 is preferably formed of a single piece of substantially resilient material.

The contact arms 27 and 28 are provided with enlarged electrical Ycontacts 29 and 30 respectively which are disposed adjacent the midportion thereof. The back plate 25 isxadapted to slidably tit within the grooves 21, while the-contact arms 27 Yand 23 extend downwardly through-opening 22 to yadjacent the lowered ge of the body member 10. Contact element 24 is so formed that corr- Atact arms 27 and 28 extend at an angle with respect to plate 25. When plate is disposed in grooves 21, contact arms 27 and 28 extend downwardly and lat a slight angle away from plate`25.

An identically formed contact element 24a has identical parts 25a-30a. Contact'element 24a is mounted in the grooves 21 opposite from contact element 24.

The inner sides of openings 22 and 23 are provided with two fixed electrical contact plates 31 and 32 on the side thereof yadjacent to contact element 24 and two identical contact plates 33 and 34 on the opposite side adjacent to contact element 24a. Contact plates 31 and 33 are actually part of a single U-shaped member which is attached -to the underside of the floor of compartment 11 by a rivet, which extends therethrough. ContactV plates 32 `and 34 are likewise parts of another U-shaped member which is held by `a rivet.

The electrical contacts 29 and 30 on contact element 24 normally engage contact plates 31 and 32 and are held in electrical contact therewith by their own resilience. The electrical contacts 29a `and 30a similarly normally engage contact plates 33 and 34.

The rear contact compartment 12 is formed identically with the front contact compartment 11. It has two pairs of oppositely disposed grooves 21a and va pair of openings 22a and 23a in the front thereof. A pair of contact elements 24h and 24C have identical parts 25b-33b and 25e- 30e respectively. Identical parts 31a-36a are also provided in rear compartment 12, being the same as parts 31-36.

The coils 15 `and 16 comprise a large number of windings of electrical wire around a central core. The ends of the wires of coil 15 are connected to the top portions 26 and 26a of contact elements 24 and 24a. One end of coil 15 is thus in electrical contact with contact `arms 27 and 23 and their contacts 29 and 30. The other end of coil 15 is in ele-ctrical contact with contact arms 27a and 23a and their contacts 29a and Stia. The leads of coil 16 are similarly connected to the top portions 2611 and 26e and are electrically connected to contacts 29b and 30b and contacts 29e and 30C respectively.

Mounted within the lower part of body member 1? beneath coil compartment 13 is an elongated cylindrical armature 35, which is preferably formed of electrically non-conductive plastic such as Lucite or the like. Extending through the cylindrical armature transversely to the longitudinal axis thereof Iare a pair of small permanent magnets 36 and 37. These permanent magnets are substantially square in shape and are equal in length to the diameter of armature 35, so that the ends of magnets 36 Iand 37 are substantially flush with the outer circumference of armature 35. Magnets 36 'and 37 are disposed between the lower ends of poles 17-20.

The front portion of armature 35 is provided with an integral cylindrical front end portion 38, which carries a pair of integral front cam lobes 39 and.40. These cam lobes are disposed `on diametrically opposite sides of end portion 38. The sides of front cam lobes 39 and 40 are parallel to each other, extending Yon -a line from the sides of end portion 38. The ends of cam lobes 39 and 40 `are arcuate and concentric with end portion 33 and armature 35.

A front drive shaft 41 extends into the center of end portion 38 and is journaled in a front bearing 42, which extends downwardly from adjacent the front of the front contact compartment 11. VThe drive shaft 41 carries a worm gear 43, which is disposed' beyond 'bearing 42.

A pair of front wheel plates 44 is mounted on the side of body member 10 adjacent the front and bottom thereof. A front axle 45 is rotatably mounted in a pair of openings in the front wheel plates 44. The front 'axle 45 extends transversely into body member 10 and carries a pair of front wheels 46 and 47, which are disposed adjacent wheel plates 44. Wheels 46 and 47 may be flanged for use on tracks. Front axle 45 also carries adjacent the center thereof a gear 48, which meshes with the gear 43 carried by drive shaft 41. Rotary movement of drive shaft 41 is thus translated into rotary movement of front wheels 46 and 47 to move body member 10 in a forward or rearward direction.

The rear end of body member 10 is provided with parts which are identical with the above described parts 38-43. These are identied as parts 38a43a, the numbers corresponding to those set forth above.

The contact plates 31 and 33 are electrically connected to one side of a ysuitable source of direct current electrical supply. In practice, a six to twelve volt supply has been found satisfactory. The Contact plates 32a and 34a are electrically connected to the other side of the electrical supply. Such connections may be made through wires which are connected to the mounting rivets of the contact plates as shown in the drawings. The contact plates 32 and 34 are electrically connected to contact plates 31a and 33a by a connection which is not shown in the drawings.

In operation, the action of the cam lobes in making Iand breaking electrical contacts is `best understood by reference to Figs. 3-6 of the drawings, while the electrical circuits involved are best understood by reference to Figs. 9-16 of the drawings.

When the circuit to the electrical source of supply is closed, current iows through one or both of coils 15 and 16, depending upon the positioning of the electrical contacts. The ow of current through coils 15 and 16 causes a magnetic field to be created, with One of the associated poles being polarized opposite to the other. The magnetic field so created attracts magnets 36 and 37 in the same direction, causing rotation of the armature 35.

As the armature 35 rotates, cam lobes 39 and 43 rotate with it. As the cam lobes 39 and 4t) rotate, they engage the adjacent contact arms 27-23a, moving them against their natural resilience away from the center of body member 1t?. Whenever a contact arm is moving away from the -center of body member 10, an electrical contact is opened between the contact side by the contact arm and the associated Contact plate.

Cam lobes 39a and 40a are simultaneously rotated, but since they are displaced ninety degrees from cam lobes 39 and 40, the opening and closing of electrical circuits in the front of body member 1d is ninety degrees out of phase with the opening and closing of electrical circuits in the back of body member 1t?.

Referring to Fig. 3 of the drawings, this shows cam lobe 49a in engagement with contact arm 28h, opening the circuit `between contact 30b and contact plate 32a. Cam lobe 39a is in engagement with contact arm 27C, opening the circuit between electrical contact 29C and Contact band 33a. The other circuits associated with cam lobes 39a and 40a are closed, namely the contact between electrical contact 29]) and contact plate Sia and between `electrical contact 428C and con-tact plate 34e. An electrical circuit is completed through these closed contacts to cause current to flow through coil 16. This is best shown by reference to Fig. 9 of the drawings, which corresponds to Fig. 3.

The cam lobes 39 and 40 are out of engagement with their associated contact arms and all of the electrical contacts associated with them are accordingly closed. This results in the electrical circuit through coil i5 being short-circuited, so that no current is applied to coil i5.

The flow yof current through coil 16 creates a magnetic field which polarizes its poles 19 land 2i?, causing magnet 37 to be attracted toward pole 19 and resulting in clockwise rotation of armature 35. This rotation causes the wheels to turn, moving body member i9.

The sequential operation `of my motor from this point on can best be understood by reference to Figs, 9-l6. As armature 35 rotates, it brings the other cam lobes 39 and 40 into engagement with their contact arms to open -circuit to coil 16.

the short circuit or coil 15. Current then flows through yboth coils and 16, as shown inFig. 10. The magnetic Ystart of the cycle, camlobes 39a and 40a move out of "engagement with their Contact arms and their associated contacts are all closed. This'short-circuits the electrical lt will be noted that a substantial vamount oi arcing is avoided by not opening the circuit through -coil 1d when the full current iiow is passing through it. linstead, the coil is short-circuited to prevent the application ot further voltage tothe coil and permit its current tlow to decreasebefore its contactsare opened.

VThis condition ofthe circuits is shown in Fig. 11 of the drawings. It will be noted that current continues t-o flow through coil 15, causing continued rotation of armatube 35. In this connection, it will be noted that the full amount ot'applied yelectrical current is utilized at all times. Whenever one coil is short-circuited, the full amount of current is applied to the other coil. VrlVhenever both coils lare connected, the current tlows through them in series.

with Fig. 9 following Fig.` 16 to start la new sequence.

It will be noted that my toy locomotive is self-starting because one of magnets 36 and 37 is always disposed at eastrpartially transversely to the lines `of magnetic force between two related armatures.

Instead of the electrical connections shown, the coils 15 and 16 could be contacted in parallel rather than in series. It would not, however, be possible to short-circuit one of the coils if they were connected in parallel. It is also possible to use only one coil Ior to use a second coil only for starting the locomotive.

The speed of-my locomotive can be controlled by a rheostat which vregulates the amount lof voltage applied -to the coils. The direction of movement of my toy locomotive can be yreversed `by reversing the polarity of the applied voltage.

Instead of the electrical connections shown, the wheels may be insulated from each other and current picked up by the wheels from a pair of tracks. Since the armature 35 is non-conductive, my toy locomotive can easily be made to operate in this manner.

In the embodiment selected for illustration in the drawings, electrical current from a suitable source of direct current supply is connected to thetwo wires shown `on the right of Fig. l. These wires are electrically connected to contact plates 32a and 34a and contact plates 31 and 33 respectively. A exible electrical wire is connected at one end to these Wires and at the other end to the battery or other source of supply. In case rails are used, the source of electrical supply would be connected to the rails and current drawn therefrom through the wheels in a conventional manner.

ln some of the illustrations, the cam lobes have been shown for purposes of illustration in a position slightly oiset to one side or the other of the contact arms. In practice, the cam lobes `and contact arms are preferably aligned. They have been shown as offset to permit 'better understanding of the invention.

1 claim:

l. An electrically driven device comprising an elongated body member having a contact compartment ydisposed in the upper portion thereof adjacent each end thereof and a. coil compartment disposed therebetween, each of said contact compartments having a pair ofY grooves adjacent 6 each side thereof, a contact element slidably mounted in said grooves in each'.4 side of said contact compartments,

' each of said contact elements having a pair of resilient elongated contact arms extending downwardly from ad- -jacent thetopot" said body memberl to adjacentv the bottom thereof, -two pairs of contact platesdisposed adjacent the center of'each of sai-d contact compartments, one pair of said contact plates normally being in elec# -trical contact `with each pair of oppositely disposed contact arms, two pairs of oppositely disposed slots extending through the bottom of said coil compartment, a pair of cores slidablyV mounted in said coil compartment, each of said cores having a plurality of coil windings `extending therearound and an elongated stationary pole disposed at each end thereof, said poles extending through saidk openings toadjacent' the bottom of said body member, said cores being in-frictional engagement with the sides and ends'of said coil compartment and with each other, an elongated armature member rotatably mounted in the bottom of said body member and extending longitudinally therealong, said elongated armature member having a pair ofpermanent magnets disposed therein, said magnets extending diametrically across said elongated armature member at right angles to each other, each of said'magnets'lbeingldisposedsubstantially between the poles `of one of said cores, said elongated armature member having a pair of oppositely disposed cam lobes at each end thereof, one of said cam lobes being disposed adjacent the lower yends ot each pair of said contact arms, said camlobes atone end of said elongated armature member'being disposed at a right angle to those on the opposite end of said elongated armature member, a gear connected to each end 4of said elongated armaturesmer'nber-and adapted to be rotated thereby, a sec- `ond gear meshed with each of said gears, each of said 4second gears being 'connected to an axle extending trans verselyacross the Vend of `said body member, each of said axles being rotatably mounted and carrying a pair ot wheels at the ends thereof, the opposite ends of each of said coil windings being electrically connected to one pair ofzsaid oppositely-disposed contact elements, one pair of said contact plates at each end of said body member adapted to be electrically connected to one side or' a source of direct current electrical supply, the other pairs of said contact plates being electrically connected to each other, each `of said cam lobes adapted upon rotation of said elongated armature member to engage the lower ends of said adjacent :contact arms and move the same outwardly toopen the electrical contacts between said contact arms and their adjacent contact plates, the tiow of electrical current through said windings creating magnetic fields `which react with said permanent magnets to cause said elongated armature member to rotate, said cam lobes rotating to open and close the `electrical contacts between said contact arms and contact plates so that the volta-ge applied to said windings is reversed sub stantially simultaneously with the reversal in positioning ot said magnets for continued rotation of said elongated armature member.

2. An electrically driven device comprising an elongated body member having a contact compartment disposed in the upper portion thereof adjacent each end thereof and a coil compartment disposed therebetween, a pair of oppositely disposed contact elements slidably mounted in each of said contact compartments, each of said contact elements having a pair of resilient elongated contact arms, two pairs of contact plates disposed between said contact arms, one pair of lsaid contact plates normally being in electrical Contact withv each pair of oppositely disposed contact arms, a pair of cores slidably mounted in said coil compartment, `each of said cores having a plurality of coil windings extending therearound and an elongated stationary pole disposed at each end thereof, an elongated armature rotatably mounted in said body member, said elongated armature carrying a pair of permanent magnets, said magnets being disposed at right angles to each other,

each `of said magnets `being disposed substantially between the poles of one of said cores, said elongated armature having a pair of oppositely disposed cam lobes at each end thereof, one of said cam lobes being disposed between e'ach pair of opposed contact arms, said cam lobes at one end of said armature being disposed at a right angle to those on the opposite end of said armature, a pair `of wheels connected to each end of said armature, the opposite -ends of `each of said windings being electrically connected to one pair of said oppositely disposed conta-ct elements, one pair of said contact plates at each end of said body member adapted to be electrically connected to `one side of a source of direct current electrical supply, the other pairs of said contact plates being electrically connected to each other, each of said cam lobes adapted upon rotation of said armature to engage said adjacent contact arms and move the same outwardly to open the electrical contacts between said contact arms and their adjacent contact plates, the ow of lelectrical current through the windings of said coils creating magnetic elds which react with said permanent magnets to cause said armature to rotate, said cam lobes rotating to open and close the electrical contacts between said contact arms and contact plates so that the voltage applied to said windings is reversed substantially simultaneously with the reversal in positioning of said magnets.

3. An electric motor for toy locomotives and t-he like comprising a body member, a pair of oppositely disposed contact yelements :removably mounted in said body member, each of said contact elements having a pair of contact arms, two pairs of contact plates Idisposed between said contact arms, one pair of said contact plates normally being in electrical contact with each pair of oppositely disposed contact arms, a pair of cores removably mounted in said body member, each yof said cores having a plurality of coil windings extending therearound and Ia stationaiy pole disposed at each end thereof, an armature rotatably mounted in said body member, sai-d armature carrying a pair of permanent magnets, said magnets extending at right angles to each other, each of said magnets being disposed substantially between the poles of one of said coils, said armature having a pair of oppositely -disposed cam lobes at each end thereof, one of said cam lobes being disposed between each pair of opposed contact arms, one pair of lsaid cam lobes being disposed at a right angle to 'theV other pair, the opposite ends of each of said windings being electrically tact plate adjacent thereto, a pair of electrical cores carrying coils, each of said cores having a pair of stationary poles, each of said coils being electrically connected to one opposed pair of said contact elements, one of said pairs of contact plates adapted to be connected to one side of a source of direct current supply, another of said pairs of contact plates adapted to be connected to the other side of said source of supply, the remaining pairs of contact plates being electrically connected to each other, a rotatable armature having a pair of permanent magnets, said magnets being disposed at right angles with respect to each other, a pair of contact open- Y ing members disposed between each of said pairs of opposed contact elements, said contact opening members being rotatable by said armature, one pair of said contact opening members being operable 90 out of phase with the other, each of said coils adapted upon energization thereof to create a magnetic eld between its poles, said magnetic eld reacting with said permanent magnets to cause said armature to rotate and said contact opening members rotate therewith to open and close the electrical circuits to said coils so as to reverse the direction of current ow through said coils for continued rotation of said armature.

6. An electric motor for toy locomotives and the like comprising a pair of contact elements disposed opposite each other, each of said contact elements having a pair of contact arms, a pair of contact plates disposed between each opposed pair of contact arms, each of said arms normally being in electrical contact with the contact plate adjacent thereto, an electrical core carrying a coil and having a pair of stationary poles, the opposite ends of said coil being electrically connected to said contact elements, a rotatable armature having a permanent magnet, said magnet being disposed between said poles, a pair of oppositely disposed contact opening members disposed between the oppositely disposed contact arms of said contact elements, said contact opening members being rotatable by said armature, said coil adapted upon direct current flowing therethrough to create a magnetic eld between said poles, said magnetic field acting upon said magnet to cause said armature to rotate,

said armature rotating said contact opening members to open said normally closed contacts alternately to reverse said magnetic field substantially simultaneously with the reversal of positioning of said permanent magnet for continued rotation of said armature.

connected to one pair of said oppositely disposed contact 4 elements, two pairs of said contact plates adapted to be electrically connected to `one side of a source of direct current electrical supply, the other two pairs -of said contact plates being electrically connected to each other, each of said cam lobes adapted yupon rotation of said armature to engage its adjacent contact arms and move the same outwardly to vopen the electrical contacts between said contact arms and their adjacent contact plates, the fiow of electrical current through said windings creating magnetic elds which react with said permanent magnets to cause said armature to rotate, said cam lobes rotating to open and close the electrical contacts 'between said contact arms `and Contact plates so that the voltage applied to .said windings is reversed substantially simultaneously with the reversal in positioning of said magnets.

4. The subject matter of claim 3, said coils being connected in series with each other, the electrical circuit to each of said coils being short-circuited between each reversal of polarity of the voltage applied thereto.

5. An electric motor for toy locomotives and the like comprising two pairs of contact elements disposed opposite each other, each of lsaid contact elements having a pair of contact arms, a pair of contact plates disposed between each opposed pair of contact arms, each of said arms normally being in electrical contact with the con- 7. An electrical motor for toy locomotives and the like comprising a core carrying a coil and having a pair of stationary poles, a rotatable armature carrying a permanent magnet, said magnet being disposed within the magnetic field of said poles, and means carried by said armature for reversing the polarity of voltage applied to said coil substantially simultaneously with reversal of the positioning of Asaid magnet caused by the rotation of sald armature.

8. rThe subject matter of claim 7, the electrical circuit to said coil being short-circuited between each reversal 'i of poles, said armature having a pair of oppositely disposed cam lobes at each end thereof, said cam lobes at one end of said armature being disposed at right angles to the cam lobes at the opposite end of said armature, each of said coils having a pair of contact arms electrically connected therewith, said cam lobes being adapted to move said contact arms upon rotation of said armature to reverse the polarity of voltage applied to said coils substantially simultaneously with reversal l of the positioning of said magnets caused by rotation of avons/o4 said armature, the electrical circuit to each of said coils being short-circuited between each reversal of the voltage applied thereto.

l0. An electrically driven device comprising an elongated body member having a contact compartment disposed in the upper portion thereof adjacent each end thereof and a coil compartment disposed therebetween, a pair of contact elements mounted in each of said contact compartments, each of said contact elements having a pair of resilient contact arms extending downwardly, two pairs of contact plates disposed adjacent the center of each of said contact compartments, one pair of said contact plates normally being in electrical contact with each pair of oppositely disposed contact arms, a pair of cores mounted in said coil compartment, each of said cores having a plurality of coil windings extending therearound and an elongated stationary pole disposed at each end thereof, an elongated armature member rotatably mounted in the bottom of said body member and extending longitudinally therealong, said elongated armature member having a pair of permanent magnets, said magnets extending at right angles to each other, each of said magnets being disposed substantially between the poles of one of said cores, said armature member having a pair of oppositely disposed cam lobes at each end thereof, one of said cam lobes being disposed adjacent the lower ends of each pair of said contact arms, said cam lobes at one end of said elongated armature member being disposed at a right angle to those on the opposite end or" said armature member, each of said cam lobes adapted upon rotation of said armature member to engage the lower ends of said adjacent contact arms and move the same outwardly to open the electrical contacts between said contact arms and their adjacent contact plates, the ow of the electrical current through said windings creating magnetic fields which react with said permanent magnets to cause said armature member to rotate, said cam lobes rotating to open and close the electrical contacts between said contact arms and contact plates so that the voltage applied to said windings is reversed substantially simultaneously with the reversal in positioning of said magnets for continued rotation of said armature member.

l1. In an electrically driven device, a body member having a coil compartment, said coil compartment having a pair of oppositely disposed grooves extending through the bottom thereof, a core slideably and removably mounted within said coil compartment, said core having a plurality of windings extending therearound, said core having a stationary pole at each end thereof, said poles extending through the grooves in said coil compartment.

l2. In an electrically driven device, a body member having a contact compartment, said contact compartment having a pair of oppositely disposed grooves extending through the bottom thereof, a pair of contact elements removably and slideably mounted within said contact compartment, each of said contact elements having a pair of resilient contact arms extending through said grooves and two pairs of contact plates mounted between said Contact arms, said contact arms normally being in electrical contact with said contact plates.

13. In an electrically driven device, a body member having a coil compartment, said coil compartment having a pair of oppositely disposed grooves extending through the bottom thereof, a core slideably and removably mounted within said coil compartment, said core having a plurality of windings extending therearound, said core having an elongated stationary pole disposed at each end thereof, said poles extending through the grooves in said coil compartment, said body member having a contact compartment, said contact compartment having a pair of oppositely disposed grooves extending through the bottom thereof, a pair of contact elements slideably and removably mounted in said contact compartment, each of said contact elements having a pair of resilient contact arms extending through said grooves, two pairs of contact plates mounted between said contact arms, said contact arms normally being in electrical contact with said contact plates, and an armature carrying a permanent magnet, said magnet being disposed within the tield of said poles, said armature carrying means for opening the contacts between said contact arms and said contact plates whereby the polarity of voltage applied to said coil is reversed substantially simultaneously with the reversal of the positioning of said magnet caused by the rotation of said armature.

14. In an electrically driven device, a body member having a coil compartment, a core slideably and removably mounted within said coil compartment, said core having a plurality of windings extending therearound, said core having an elongated stationary pole disposed at each end thereof, said body member having a contact compartment, a pair of contact elements slideably and removably mounted in said contact compartment, each of said Contact elements having a pair of resilient contact arms, two pairs of contact plates mounted between said contact arms, said contact arms normally being in electrical contact with said contact plates, and a rotatable armature carrying a permanent magnet, said magnet being disposed within the iield of said poles, said armature carrying means for opening the contacts between said contact arms and contact plates whereby the polarity of voltage applied to said coil is reversed substantially simultaneously with the reversal of the positioning of said magnet caused by the rotation of said armature.

References Cited in the file of this patent UNITED STATES PATENTS 

